Methods of treating pain using antagonists of il-31, il-31ra and/or osmrb

ABSTRACT

Use of antagonists to IL-31Ra and OSMRb are used to treat inflammation and pain by inhibiting, preventing, reducing, minimizing, limiting or minimizing stimulation in neuronal tissues. Such antagonists include soluble receptors, antibodies and fragments, derivative, or variants thereof. Symptoms such as pain, tingle, sensitization, tickle associated with neuropathies are ameliorated.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a divisional of U.S. application Ser. No. 11/621,840, filed Jan. 10, 2007, which claims the benefit of U.S. Provisional Application Ser. No. 60/758,066, filed Jan. 10, 2006, U.S. Provisional Application Ser. No. 60/757,979, filed Jan. 10, 2006, U.S. Provisional Application Ser. No. 60/773,031, filed Feb. 14, 2006, U.S. Provisional Application Ser. No. 60/805,552, filed Jun. 22, 2006, U.S. Provisional Application Ser. No. 60/805,550, filed Jun. 22, 2006, U.S. Provisional Application Ser. No. 60/805,554, filed Jun. 22, 2006, U.S. Provisional Application Ser. No. 60/823,982, filed Aug. 30, 2006, and U.S. Provisional Application Ser. No. 60/823,987, filed Aug. 30, 2006, all of which are herein incorporated by reference.

BACKGROUND OF THE INVENTION

The inflammatory process activates the nervous system causing inflammatory pain and a disruption in motor function. Stimulation of sensory nerves produces vasodialtion and plasma extravasation, leading to neurogenic inflammation and stimulation causing sensory irritation, hypersensitivity and pain.

Neurogenic inflammation is caused by activation of nociceptive and thermal-sensitive endings in tissues and can be caused by innate conditions, such as autoimmune diseases, including allergy, by viral infection, as well as by injury. The neurogenic inflammation from these conditions can affect the somatosensory system, which consists of various sensory receptors responsible for sensations such as pressure, touch, temperature, pain, itch, tickle, tingle, and numbness. Activated nerves can perpetuate chronic inflammation by inducing secretion of cytokines, activating monocytes and chemotaxis.

Proteins active in neurogenic inflammation can serve as targets for therapeutic approaches to diagnosis and treatment of diseases.

An example of a drug used to treat pain is Neurontin (gabapentin), which is used to treat diabetic peripheral neuropathy as post-herpatic neuralgia. Thus, there is a need for additional medication to treat neuropathic pain.

DESCRIPTION OF THE INVENTION

The following definitions are provided to facilitate understanding of the inventions described herein.

The term “antibody” or “antibody peptide(s)” refers to an intact antibody, or a binding fragment thereof that competes with the intact antibody for specific binding and includes chimeric, humanized, fully human, and bispecific antibodies. In certain embodiments, binding fragments are produced by recombinant DNA techniques. In additional embodiments, binding fragments are produced by enzymatic or chemical cleavage of intact antibodies. Binding fragments include, but are not limited to, Fab, Fab′, F(ab′).sub.2, Fv, and single-chain antibodies.

The term “isolated antibody” refers to an antibody that has been identified and separated and/or recovered from a component of its natural environment. Contaminant components of its natural environment are materials which would interfere with diagnostic or therapeutic uses for the antibody, and may include enzymes, hormones, and other proteinaceous or nonproteinaceous solutes. In embodiments, the antibody will be purified (1) to greater than 95% by weight of antibody as determined by the Lowry method, and including more than 99% by weight, (2) to a degree sufficient to obtain at least 15 residues of N-terminal or internal amino acid sequence by use of a spinning cup sequenator, or (3) to homogeneity by SDS-PAGE under reducing or nonreducing conditions using Coomassie blue or, preferably, silver stain. Isolated antibody includes the antibody in situ within recombinant cells since at least one component of the antibody's natural environment will not be present. Ordinarily, however, isolated antibody will be prepared by at least one purification step.

A “variant” anti-IL-31 antibody, refers herein to a molecule which differs in amino acid sequence from a “parent” anti-IL-31 antibody amino acid sequence by virtue of addition, deletion and/or substitution of one or more amino acid residue(s) in the parent antibody sequence. In an embodiment, the variant comprises one or more amino acid substitution(s) in one or more hypervariable region(s) of the parent antibody. For example, the variant may comprise at least one, e.g. from about one to about ten, and from about two to about five, substitutions in one or more hypervariable regions of the parent antibody. Ordinarily, the variant will have an amino acid sequence having at least 75% amino acid sequence identity with the parent antibody heavy or light chain variable domain sequences, more preferably at least 80%, more preferably at least 85%, more preferably at least 90%, and most preferably at least 95%. Identity or homology with respect to this sequence is defined herein as the percentage of amino acid residues in the candidate sequence that are identical with the parent antibody residues, after aligning the sequences and introducing gaps, if necessary, to achieve the maximum percent sequence identity. None of N-terminal, C-terminal, or internal extensions, deletions, or insertions into the antibody sequence shall be construed as affecting sequence identity or homology. The variant retains the ability to bind human IL-31 and preferably has properties which are superior to those of the parent antibody. For example, the variant may have a stronger binding affinity, enhanced ability to inhibit IL-31-induced stimulation of immune cells. To analyze such properties, one should compare a Fab form of the variant to a Fab form of the parent antibody or a full length form of the variant to a full length form of the parent antibody, for example, since it has been found that the format of the anti-IL-31 antibody impacts its activity in the biological activity assays disclosed herein. The variant antibody of particular interest herein is one which displays at least about 10 fold, preferably at least about 20 fold, and most preferably at least about 50 fold, enhancement in biological activity when compared to the parent antibody.

The term “parent antibody” as used herein refers to an antibody which is encoded by an amino acid sequence used for the preparation of the variant. Preferably, the parent antibody has a human framework region and, if present, has human antibody constant region(s). For example, the parent antibody may be a humanized or human antibody.

The term “agonist” refers to any compound including a protein, polypeptide, peptide, antibody, antibody fragment, large molecule, or small molecule (less than 10 kD), that increases the activity, activation or function of another molecule. IL-31 agonists cause, for example: stimulation of NK cells, T cell subsets and B cell subsets and dendritic cells.

The term “antagonist” refers to any compound including a protein, polypeptide, peptide, antibody, antibody fragment, large molecule, or small molecule (less than 10 kD), that decreases the activity, activation or function of another molecule. IL-31Ra and OSMRb antagonists cause: decreased immune function of NK cells, T cell subsets and B cell subsets and dendritic cells; bind IL-31 such that the interaction of IL-31 protein is blocked, inhibited, reduced, antagonized or neutralized.

A “bivalent antibody” other than a “multispecific” or “multifunctional” antibody, in certain embodiments, is understood to comprise binding sites having identical antigenic specificity.

A “bispecific” or “bifunctional” antibody is a hybrid antibody having two different heavy/light chain pairs and two different binding sites. Bispecific antibodies may be produced by a variety of methods including, but not limited to, fusion of hybridomas or linking of Fab′ fragments. See, e.g., Songsivilai & Lachmann, Clin. Exp. Immunol 79:315-321 (1990); Kostelny et al., J. Immunol. 148:1547-1553 (1992).

The term “chimeric antibody” or “chimeric antibodies” refers to antibodies whose light and heavy chain genes have been constructed, typically by genetic engineering, from immunoglobulin variable and constant region genes belonging to different species. For example, the variable segments of the genes from a mouse monoclonal antibody may be joined to human constant segments, such as gamma 1 and gamma 3. A typical therapeutic chimeric antibody is thus a hybrid protein composed of the variable or antigen-binding domain from a mouse antibody and the constant domain from a human antibody, although other mammalian species may be used.

The term “epitope” includes any protein determinant capable of specific binding to an immunoglobulin or T-cell receptor. Epitopic determinants usually consist of chemically active surface groupings of molecules such as amino acids or sugar side chains and usually have specific three dimensional structural characteristics, as well as specific charge characteristics. More specifically, the term “IL-31Ra epitope” as used herein refers to a portion of a IL-31Ra polypeptide having antigenic or immunogenic activity in an animal, preferably in a mammal, and most preferably in a mouse or a human. An epitope having immunogenic activity is a portion of a IL-31Ra polypeptide that elicits an antibody response in an animal. An epitope having antigenic activity is a portion of a IL-31Ra polypeptide to which an antibody immunospecifically binds as determined by any method well known in the art, for example, by immunoassays. Antigenic epitopes need not necessarily be immunogenic.

The term “epitope tagged” when used herein refers to the anti-IL-31Ra antibody fused to an “epitope tag”. The epitope tag polypeptide has enough residues to provide an epitope against which an antibody can be made, yet is short enough such that it does not interfere with activity of the IL-31Ra antibody. The epitope tag preferably is sufficiently unique so that the antibody does not substantially cross-react with other epitopes. Suitable tag polypeptides generally have at least 6 amino acid residues and usually between about 8-50 amino acid residues (preferably between about 9-30 residues). Examples include the flu HA tag polypeptide and its antibody 12CA5 (Field et al. Mol. Cell. Biol. 8:2159-2165 (1988)); the c-myc tag and the 8F9, 3C7, 6E10, G4, B7 and 9E10 antibodies thereto (Evan et al., Mol. Cell. Biol. 5(12):3610-3616 (1985)); and the Herpes Simplex virus glycoprotein D (gD) tag and its antibody (Paborsky et al., Protein Engineering 3(6):547-553 (1990)). In certain embodiments, the epitope tag is a “salvage receptor binding epitope”. As used herein, the term “salvage receptor binding epitope” refers to an epitope of the Fc region of an IgG molecule (e.g., IgG₁, IgG₂, IgG₃, or IgG₄) that is responsible for increasing the in vivo serum half-life of the IgG molecule.

The term “fragment” as used herein refers to a peptide or polypeptide comprising an amino acid sequence of at least 5 contiguous amino acid residues, at least 10 contiguous amino acid residues, at least 15 contiguous amino acid residues, at least 20 contiguous amino acid residues, at least 25 contiguous amino acid residues, at least 40 contiguous amino acid residues, at least 50 contiguous amino acid residues, at least 60 contiguous amino residues, at least 70 contiguous amino acid residues, at least contiguous 80 amino acid residues, at least contiguous 90 amino acid residues, at least contiguous 100 amino acid residues, at least contiguous 125 amino acid residues, at least 150 contiguous amino acid residues of the amino acid sequence of a IL-31Ra polypeptide or an antibody that immunospecifically binds to a IL-31Ra polypeptide.

As used herein, the term “immunoglobulin” refers to a protein consisting of one or more polypeptides substantially encoded by immunoglobulin genes. One form of immunoglobulin constitutes the basic structural unit of an antibody. This form is a tetramer and consists of two identical pairs of immunoglobulin chains, each pair having one light and one heavy chain. In each pair, the light and heavy chain variable regions are together responsible for binding to an antigen, and the constant regions are responsible for the antibody effector functions.

Full-length immunoglobulin “light chains” are encoded by a variable region gene at the NH2-terminus and a kappa or lambda constant region gene at the COOH— terminus. Full-length immunoglobulin “heavy chains”, are similarly encoded by a variable region gene and one of the other aforementioned constant region genes (about 330 amino acids). Heavy chains are classified as gamma, mu, alpha, delta, or epsilon, and define the antibody's isotype as IgG (including IgG1, IgG4), IgM, IgA, IgD and IgE, respectively. Within light and heavy chains, the variable and constant regions are joined by a “J” region of about 12 or more amino acids, with the heavy chain also including a “D” region of about 10 more amino acids. (See generally, Fundamental Immunology (Paul, W., ed., 2nd ed. Raven Press, N.Y., 1989), Ch. 7 (incorporated by reference in its entirety).

An immunoglobulin light or heavy chain variable region consists of a “framework” region interrupted by three hypervariable regions. Thus, the term “hypervariable region” refers to the amino acid residues of an antibody which are responsible for antigen binding. The hypervariable region comprises amino acid residues from a “Complementarity Determining Region” or “CDR” (See, Kabat et al., Sequences of Proteins of Immunological Interest, 5th Ed. Public Health Service, National Institutes of Health, Bethesda, Md. (1991) and Chothia and Lesk, 1987, J. Mol. Biol. 196: 901-917) (both of which are incorporated herein by reference). “Framework Region” or “FR” residues are those variable domain residues other than the hypervariable region residues as herein defined. The sequences of the framework regions of different light or heavy chains are relatively conserved within a species. Thus, a “human framework region” is a framework region that is substantially identical (about 85% or more, usually 90-95% or more) to the framework region of a naturally occurring human immunoglobulin. The framework region of an antibody, that is the combined framework regions of the constituent light and heavy chains, serves to position and align the CDR's. The CDR's are primarily responsible for binding to an epitope of an antigen.

Accordingly, the term “humanized” immunoglobulin refers to an immunoglobulin comprising a human framework region and one or more CDR's from a non-human (usually a mouse or rat) immunoglobulin. The non-human immunoglobulin providing the CDR's is called the “donor” and the human immunoglobulin providing the framework is called the “acceptor”. Constant regions need not be present, but if they are, they must be substantially identical to human immunoglobulin constant regions, i.e., at least about 85-90%, preferably about 95% or more identical. Hence, all parts of a humanized immunoglobulin, except possibly the CDR's, are substantially identical to corresponding parts of natural human immunoglobulin sequences. A “humanized antibody” is an antibody comprising a humanized light chain and a humanized heavy chain immunoglobulin. For example, a humanized antibody would not encompass a typical chimeric antibody as defined above, e.g., because the entire variable region of a chimeric antibody is non-human.

As used herein, the term “human antibody” includes and antibody that has an amino acid sequence of a human immunoglobulin and includes antibodies isolated from human immunoglobulin libraries or from animals transgenic for one or more human immunoglobulin and that do not express endogenous immunoglobulins, as described, for example, by Kucherlapati et al. in U.S. Pat. No. 5,939,598.

The term “genetically altered antibodies” means antibodies wherein the amino acid sequence has been varied from that of a native antibody. Because of the relevance of recombinant DNA techniques in the generation of antibodies, one need not be confined to the sequences of amino acids found in natural antibodies; antibodies can be redesigned to obtain desired characteristics. The possible variations are many and range from the changing of just one or a few amino acids to the complete redesign of, for example, the variable or constant region. Changes in the constant region will, in general, be made in order to improve or alter characteristics, such as complement fixation, interaction with membranes and other effector functions. Changes in the variable region will be made in order to improve the antigen binding characteristics.

In addition to antibodies, immunoglobulins may exist in a variety of other forms including, for example, single-chain or Fv, Fab, and (Fab)₂, as well as diabodies, linear antibodies, multivalent or multispecific hybrid antibodies (as described above and in detail in: Lanzavecchia et al., Eur. J. Immunol. 17, 105 (1987)) and in single chains (e.g., Huston et al., Proc. Natl. Acad. Sci. U.S.A., 85 5879-5883 (1988) and Bird et al., Science, 242:423-426 (1988), which are incorporated herein by reference). (See, generally, Hood et al., “Immunology”, Benjamin, N.Y., 2nd ed. (1984), and Hunkapiller and Hood, Nature, 323:15-16 (1986), which are incorporated herein by reference).

As used herein, the terms “single-chain Fv,” “single-chain antibodies,” “Fv” or “scFv” refer to antibody fragments that comprises the variable regions from both the heavy and light chains, but lacks the constant regions, but within a single polypeptide chain. Generally, a single-chain antibody further comprises a polypeptide linker between the VH and VL domains which enables it to form the desired structure which would allow for antigen binding Single chain antibodies are discussed in detail by Pluckthun in The Pharmacology of Monoclonal Antibodies, vol. 113, Rosenburg and Moore eds. Springer-Verlag, New York, pp. 269-315 (1994); see also International Patent Application Publication No. WO 88/01649 and U.S. Pat. Nos. 4,946,778 and 5,260,203, the disclosures of which are incorporated by reference for any purpose. In specific embodiments, single-chain antibodies can also be bi-specific and/or humanized.

A “Fab fragment” is comprised of one light chain and the C_(H1) and variable regions of one heavy chain. The heavy chain of a Fab molecule cannot form a disulfide bond with another heavy chain molecule.

A “Fab′ fragment” contains one light chain and one heavy chain that contains more of the constant region, between the C_(H1) and C_(H2) domains, such that an interchain disulfide bond can be formed between two heavy chains to form a F(ab′)₂ molecule.

A “F(ab′)₂ fragment” contains two light chains and two heavy chains containing a portion of the constant region between the C_(H1) and C_(H2) domains, such that an interchain disulfide bond is formed between two heavy chains.

The term “diabodies” refers to small antibody fragments with two antigen-binding sites, which fragments comprise a heavy chain variable domain (V_(H)) connected to a light chain variable domain (V_(L)) in the same polypeptide chain (V_(H)-V_(L)). By using a linker that is too short to allow pairing between the two domains on the same chain, the domains are forced to pair with the complementary domains of another chain and create two antigen-binding sites. Diabodies are described more fully in, for example, EP 404,097; WO 93/11161; and Hollinger et al., Proc. Natl. Acad. Sci. USA 90:6444-6448 (1993).

The term “linear antibodies” refers to the antibodies described in Zapata et al. Protein Eng. 8(10):1057-1062 (1995). Briefly, these antibodies comprise a pair of tandem Fd segments (V_(H)-C_(H1)-V_(H)-C_(H1)) which form a pair of antigen binding regions. Linear antibodies can be bispecific or monospecific.

The term “immunologically functional immunoglobulin fragment” as used herein refers to a polypeptide fragment that contains at least the variable domains of the immunoglobulin heavy and light chains. An immunologically functional immunoglobulin fragment of the invention is capable of binding to a ligand, preventing binding of the ligand to its receptor, interrupting the biological response resulting from ligand binding to the receptor, or any combination thereof.

The term “monoclonal antibody” refers to an antibody that is derived from a single clone, including any eukaryotic, prokaryotic, or phage clone, and not the method by which it is produced.

The present invention is based in part upon the discovery that the subunits of the heterodimeric receptor which binds IL-31, e.g. IL-31Ra and OSMRb, are expressed on neural cells such as dorsal root ganglion cells. Thus the present invention encompasses the use of IL-31Ra and OSMRb as antagonis, which inhibiting pain and inflammation and the symptoms of inflammatory bowel disease, Crohn's disease, pruritis, and neurogenic pain and sensitization by binding to IL-31 such that signal transduction is inhibited. The present invention also encompases the use of IL-31 agonists in improving sensitization through stimulation of the dorsal root gangion cells.

IL-31 is the HUGO name for a cytokine that has been previously described as Zcyto17rlig in a published U.S. patent application (See published U.S. patent application number 20030224487, U.S. patent application Ser. No. 10/352,554, filed Jan. 21, 2003, now issued U.S. Pat. No. 7,064,186; Sprecher, Cindy et al., 2003, incorporated herein by reference). The heterodimeric receptor for IL-31, comprises a heterodimer formed between IL-31Ra and OncostatinM receptor beta (OSMRb). IL-31Ra is the HUGO name for a protein called zcytor17 in commonly-owned U.S. published patent application number 20030215838, U.S. patent application Ser. No. 10/351,157, filed Jan. 21, 2003, herein incorporated by reference. The polynucleotide and polypeptide sequences for human IL-31 are shown in SEQ ID NOs: 1 and 2, respectively. The polynucleotide and polypeptide sequences for murine IL-31 are shown in SEQ ID NOs: 3 and 4, respectively. As used herein the term, IL-31 shall mean zcytor17lig as used in U.S. patent publication number 20030224487, as shown above. IL-31Ra has been previously described in commonly-owned U.S. patent application Ser. No. 09/892,949 filed Jun. 26, 2001, which is herein incorporated by reference.

The amino acid sequence for the OSMR, and IL-31RA receptors indicated that the encoded receptors belonged to the Class I cytokine receptor subfamily that includes, but is not limited to, the receptors for IL-2, IL-4, IL-7, Lif, IL-12, IL-15, EPO, TPO, GM-CSF and G-CSF (for a review see, Cosman, “The Hematopoietin Receptor Superfamily” in Cytokine 5(2): 95-106, 1993). The zcytor17 receptor is fully described in commonly-owned PCT Patent Application No. US01/20484 (WIPO publication No. WO 02/00721; herein incorporated by reference).

The present invention includes the use of anti-IL-31Ra and anti-OSMRb molecules, including antagonists, antibodies, binding proteins, variants and fragments, having anti-IL-31 activity. The invention includes administering to a subject the anti-IL-31Ra and or anti-OSMRb molecule and contemplates both human and veterinary therapeutic uses. Illustrative veterinary subjects include mammalian subjects, such as farm animals and domestic animals.

The native polynucleotide and polypeptide sequences for the “long” form of IL-31RA are shown in SEQ ID NOs:5 and 6, respectively. The native polynucleotide and polypeptide sequences for the “short” form of IL-31RA are shown in SEQ ID NOs:7 and 8, respectively. Additional truncated forms of IL-31RA polypeptide appear to be naturally expressed. Both forms encode soluble IL-31RA receptors. The “long” soluble IL-31RA polynucleotide and polypeptide sequences are shown in SEQ ID NOs:9 and 10, respectively. The “short” soluble IL-31RA polynucleotide and polypeptide sequences are shown in SEQ ID NOs:11 and 12, respectively. The native polynucleotide and polypeptide sequences for mouse IL-31RA are shown in SEQ ID NOs:13 and 14, respectively. The native polynucleotide and polypeptide sequences for human OSMRbeta are shown in SEQ ID NOs:15 and 16, respectively. See PCT applications WO 02/00721 and WO 04/003140, both of which are incorporated by reference. Thus, examples of antagonists of neurogenic inflammation and stimualation include a soluble IL-31Ra subunit that binds IL-31, a soluble multimer of the IL-31Ra subunit, such as a homodimer, and a soluble heterodimer of the IL-31Ra and OSMRb that binds IL-31. See Example 9 for a construction of a soluble heterodimer of IL-31Ra and OSMRb. Other soluble heterodimeric constructs and protein can be built and are described herein.

IL-31Ra and OSMRb antagonists include molecules that bind IL-31, including, soluble receptors, variants, fragments or derivatives thereof, or antibodies to IL-31Ra and/or OSMRb, that inhibit, limit, reduce, minimize, prevent, or neutralize the effect of IL-31 has on binding its cognate receptor.

In situ expression analysis revealed that IL-31RA and OSMRbeta are expressed in the spinal cord and dorsal root ganglion cells in humans. See Example 1. Therefore, IL-31 molecules, their agonists, or antagonists play a role in the maintenance of neurons and neurogenic inflammation and stimulation. This indicates that IL-31Ra and OSMRb agonists, antagonists can be used to treat a variety of neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS), Alzheimer's disease, Huntington's disease, Parkinson's disease, peripheral neuropathies, and demyelinating diseases including multiple sclerosis. The tissue specificity of IL-31RA and OSMRb suggests that IL-31 may be a growth and/or maintenance factor in the spinal cord and brain which can be used to treat spinal cord, brain or peripheral nervous system injuries.

Methods of measuring the ability of IL-31 to stimulate pain are known to one of skill in the art. For example, dorsal root gangion cells can be isolated and cultured. See Voilley, N. et al., J. Neurosci., 27(20):8026-8033, 2001. For example, dorsal root ganglion cells are prepared from Wistar adult male (5-7 weeks) and newborn rats by 0.1% collagenase dissociation and plating on collagen coated P35 dishes in DMEM plus 5% fetal calf serum. Similarly methods of isolating dorsal root ganglion cells are described by Steinhoff, M. et al. (See Steinhoff, M. et al., Nature Medicine, 6(2):151-157, 2000). Briefly, dorsal root ganglion cells are minced in cold Dulbeccos' modified Eagle's Medium (DMEM) and incubated in DMEM containing 0.05 mg/ml trypsin, 1 mg/ml collagenase, and 0.01 mg/ml DNAse I for 45-60 minutes at 37 degrees C. SBTI is added to neutralize trypsin and the suspension is centrifuged at about 1,000 g for 1 min. Neurons in the pellet are suspended in DMEM containg 10% fetal bovine serum, 5 ng/ml nerve growth factor, 2 mM glutamine, 1 mg/ml penicillin/streptomycin and DNAse I, and plated on glass coverslips coated with Matrigel. Neurons are cultured fro 3-5 days before use. Expression of IL-31Ra at the plasma membranes is verified by immunofluorescence using an antibody.

To measure the effect antagonists of IL-31Ra and/or OSMRb on IL-31 stimulation of dorsal root ganglion, intracellular calcium ion concentration is measured in the cultured neurons as described by Steinhoff et al., supra. The neurons are incubated in Hank's balanced salt solution, 20 mM HEPES, pH 7.4 containing 5 uM Fura-2/AM (Molecular Probes, Eugene, Oreg.) for 1 h at 37 degrees C. Coverslips are washed, mounted in a chamber (1 ml volume) on a Zeiss 100 TV inveted microscope and observed using a Zeiss x40 Fluar objective. Fleuorescence is measured at 340 nm and 380 nm to allow determination of calcium. Cells are exposed to IL-31 with and without other sensitization agents, and inhibition in the presence of IL-31RA and/or OSMRb antagonists is measured.

To measure the ability of an IL-31RA and/or OSMRb antagonist on IL-31 binding to its cognate heterodimeric receptor on dorsal root gangion, or neural cells in general, on pain several mediators of pain can be measured, such as for example, but not limited to, prostaglandins, substance P, CGRP, galanin, Neuropeptide Y, histamine, bradykinin, cannabinoids, and mediators of the arachinoid acid pathway.

In addition to the above in vitro methods to measure the ability of antagonists to IL-31Ra and OSMRb on pain-inducing effect of IL-31 on neural cells, several in vivo models are also useful. See, for example, Honore, P. et al., Neuroscience, 98(3):585-598, 2000. This article describes several models for inflammatory pain, neuropathic pain and cancer pain. For example, one model measures the effect of an antagonist to IL-31Ra, such as a subcutaneous injection of IL-31, with and with out the antagonist molecule, into the plantar surface of the hindpaw of a mouse. The mouse is euthanized 3 days after injection peripheral edema is measured. The effect of the IL-31Ra or OSMRb antagonist molecule to inhibit, limit, minimize, reduce, prevent, or neutralize the edema is measured. Additonal in vivo models are spinal nerve ligation, sciatic nerve transaction, sarcoma-induced bone cancer, behavioral analysis, and effects of morophine.

Another mouse model of pain is mechanical allodynia. See for example, Sweitzer, S. M. et al., J. Neuroimm., 125:82-93, 2002. Briefly, rats or mice are tested for mechanical allodynia with 2- and/or 12-g von Frey filaments. First the animals are acclimated to the procedure and baseline measurement are taken. The IL-31 is administered in varying amounts. Allodynia is characterized as an intense withdrawl of the paw to a normally non-noxious stimuli in response to IL-31 administration. Comparision is made with and without administration of the IL-31Ra and/or OSMRb antagonists molecule(s).

A proinflammatory neuropeptide, Substance P (SP), is made the dorsal ganglia and then transported to the periphery by nociceptive nerves A and C (15). SP can induce itch by releasing histamine from the mast cell granules. In the skin, SP can also cause erythema, edema and neurogenic inflammation releasing histamine, IL-1, prostaglandins and lysosomal enzymes but is quickly degraded in the dermis (16). The prior oral administration of antihistamines inhibits the pruritus caused by SP. Capsaicin obtained from hot pepper applied locally depletes SP from cutaneous nerves, and so diminishes pruritus. As the receptor subunits for IL-31 are expressed in the dorsal root ganglion cells, administration of the IL-31Ra and/or OSMRb antagonist molecules can decrease the stimulation of these cells and may decrease Substance P that may be induced by IL-31 administration.

The binding of IL-31 to its receptor, i.e., IL-31RA and OSMR beta, on dorsal root ganglion cells can stimulate the somatosensory system, which consists of various sensory receptors responsible for sensations such as pressure, touch, temperature, pain, itch, tickle, tingle, and numbness. The binding of IL-31 to its cognate receptor can result in neurogenic inflammation and stimulation, which may lead to release of additional factors that induce neurogenic stimulus. One group of factors that mediate pain is the prostaglandins, which also contribute to local inflammation. Thus, an IL-31 antagonist may have benefit in acute inflammatory pain commonly treated with NSAIDs, such as myalgia, headache, joint pains from acute injuries or chronic pain such as that caused by osteoarthritis. Such neurogenic stimulus can be the result of inflammation caused by, for example, autoimmune reactions, such as allergy, viral infection, such as varicella, and injury, such as burn or trauma. Thus, antagonists that interfere with signal transduction induced by the binding of the IL-31 ligand to its cognate receptor can be useful in reducing, limiting, preventing, or minimizing neurogenic inflammation and the stimulation of the somatosensory system. As such, antagonists of IL-31-induced signal transduction in dorsal root ganglion cells can be used to treat pain, itch, tingling, associated with autoimmune diseases, viral infection, and trauma. Moreover, since neurogenic inflammation can result in a hypersensitivity of the nerve after the initial insult, antagonists of IL-31Ra and/or OSMRb can be effective treatment of symptoms. For example, some shingles patients experience the sensory symptoms of pain and/or itch long after the viral infection has been cleared or minimized. The neuralgia that accompanies acute herpes zoster, and postherpetic neuralgia are likely due to inflammation of the dorsal root ganglia and trigeminal ganglia, where viral antigens attract T cells and other inflammatory cells. Long lasting pain may result from persistent inflammation of the dermatome following a robust antiviral response. Consequently, the level or stage of viral infection may not be representative of the sensory perception of the subject. Thus, the beneficial effect of antagonizing IL-31-induced signal transduction may extend beyond the immediate state of viral infection or trauma.

Neuropathy and sensory deficiency involve pain and loss of sensitivity, and can be related to such diseases as, atopy, diabetes, multiple sclerosis, and hypertension, for example. As IL-31RA and OSBRbeta are proteins that are expressed in the spinal cord and dorsal root ganglion cells, antagonists of IL-31Ra and/or OSMRb may be useful to treat pain and sensory deficiencies. For example, the IL-31Ra and/or OSMRb antagonists can be delivered topically, subcutaneously, centrally, or systemically, to treat diabetic peripherineuropathy, postherpatic peripheral neuropathy, as well as pain, in general, including pain as a symptom in burn patients.

Burn injuries cause intense and prolonged pain that is intensified when the wound dressing is changed. Frequent dressing changes are necessary to prevent infection and aid healing. The amount of pain experienced by patients during wound care remains a worldwide problem for burn victims as well as a number of other patient populations. When patients are at rest pain associated with burn can be treated with opioids, which have some unwanted effects. However, during wound care such as daily bandage changes, wound cleaning, staple removals etc., opioids are not enough, with a majority of burn patients reporting severe to excruciating pain during wound care.

Since both members of the heterodimer for IL-31, i.e., IL-31RA and OSMRbeta are expressed in dorsal root ganglion cells, an antagonist to IL-31Ra and/or OSMRb, such as a neutralizing antibody is useful to prevent, minimimize, limit and/or treat pain, including pain associated with burn or neuropathy. In vivo models mimicking burn are well known to one skilled in the art.

Persistent pain can provoke hyperplasia such that less than the original stimulus can cause increased pain, also called allodynia. As both the IL-31RA and OSMR beta subunits are expressed on dorsal root gangion cells, an antagonist to IL-31Ra and/or OSMRb induced signal transduction in neuronal cells bearing these subunits can help to mitigate symptoms of allodynia.

Polypeptides of the present invention, such as IL-31Ra and/or OSMRb, as well as agonists, fragments, variants and/or chimeras thereof, can also be used to increase sensitization in mammals. For example, IL-31 polypeptides of the present invention, including agonists, can be used to increase sensitization (pain, heat, or mechanical) when delivered locally or topically, systemically, or centrally and measured in any models or experiments known to one skilled in the art and/or described herein. Also, the polypeptides of the present invention can be administered to enhance the sensitivity of spinal and neuronal cells in order to improve the function of the surviving neurons to neurotransmitters and therefore might be effective in Parkinson's or Alzheimers disease, as well as paralysis.

Similarly, where a patient has an increased sensitization to pain, antagonists to IL-31Ra and/or OSMRb can be used to decrease the sensation of pain in a patient with neuropathy. For example a patient with diabetic neuropathy and postherpatic neuropathy, have chronic, enhanced pain, the antagonist to IL-31Ra and/or OSMRb may be useful to limit, prevent or decrease the pain.

As a receptor for a protein that is proinflammatory, the presence of IL-31RA and OSMRbeta in the spinal cord and dorsal root ganglion indicate that antagonists of IL-31Ra and/or OSMRb can be used to reduce inflammation in these tissues. Thus, conditions such as meningitis may benefit from administration of the antagonists, including antibodies.

Diseases which involve neurogenic inflammation and stimulation and can benefit from antagonizing IL-31 induced pain in neuronal tissues, including dorsal root ganglion cells include: chronic pain, migraines, arthritis, osteoarthritis, rheumatoid arthritis, polyneuropathy, diabetic peripheralneuropathy, pain subsequent to nerve severence (eg. post-surgical pain), inflammatory conditions that involve a neurogenic pain-producing component, such as inflammatory bowel disease, nephritis, certain metastic carcinomas, and inflammation of the blood vessels. These diseases can also be treated by an antagonist of IL-31 induced signal transduction. In addition, skin conditions, including radiation irritation and burns, chemical burns, multiple chemical sensitivity, prickly heat, rhinitis, thermal burns, sunburn, reddening of the skin and chemically induced lesions, and acute allergic reactions such as acute asthma attack and inflammation of the lung caused by chemical exposure, and hives as well as conjunctivitis and gum disease can be treated with IL-31Ra and/or OSMRb antagonists. Additionally, scapuloperoneal syndromes are heterogeneous neuromuscular disorders which are characterized by weakness in the distribution of shoulder girdle and peroneal muscles. Both neurogenic (scapuloperoneal spinal muscular atrophy, SPSMA) and myopathic (scapuloperoneal muscular dystrophy, SPMD) scapuloperoneal syndromes have been described. The chromosomal locus for SPMD has recently been assigned to chromosome 12q, which is the same locus as for IL-31. Thus, IL-31Ra and/or OSMRb antagonists can be used to treat these diseases.

In the United States approximately 500,000 people suffer from inflammatory bowel disease, which can involve either or both the small and large bowel. Ulcerative colitis and Crohn's disease are the best-known forms of inflammatory bowel disease, and both are categorized as “idiopathic” inflammatory bowel disease because the etiology for them is unknown.

Crohn's disease can involve any part of the gastrointenstinal tract, but most frequently involves the distal small bowel and colon. Inflammation can produce anything from a small ulcer over a lymphoid follicle to a deep fissuring ulcer to transmural scarring and chronic inflammation. Although the etiology is unknown, infectious and immunologic mechanisms have been proposed. Symptoms are variable and can include diarrhea, fever, and pain, as well as extra-intestinal manifestations of arthritis, uveitis, erythema nodosum, and ankylosing spondylitis.

The traditional approach to treating inflammatory bowel disease is immunosuppression with azathioprine (see, for example, Rutgeerts, J. Gastroenterol. Hepatol. 17(Suppl.):5176-85 (2002)). More recently, the chimeric monoclonal anti-tumor necrosis factor antibody, infliximab, has been used to target specific pathogenic disease mechanisms, and allows thorough suppression of the disease process and healing of the bowel in the long term. However, this therapy is associated with problems of immunogenicity. The formation of antibodies to infliximab interferes with efficacy and is associated with infusion reactions.

Irritable bowel syndrome (IBS) is a chronic functional gastrointestinal disorder. It is a heterogeneous condition characterized by a variety of bowel symptoms including abdominal pain and bloating which are usually associated with altered bowel habit (Collins et al, 2001). It is estimated that between 12 and 20% of the U.S. population suffer from this condition. Differing criteria have been proposed for defining IBS, including the Manning criteria (Manning et al, 1978), the Rome criteria (Thompson et al, 1992), and most recently Rome II (Thompson et al., 1999). Research reports on IBS frequently classify patients with IBS into the two subtypes of constipation predominant (CON) and diarrhea predominant (DIA) and sometimes include a third subtype of alternating pattern (ALT).

Anti-IL-31Ra and/or anti-OSMRb molecules, antagonists, antibodies, binding proteins, variants and fragments, are useful in treating, detecting, and pain associated with Inflammatory Bowel Disease (IBD) and Irritable Bowel Syndrome (IBS).

Inflammatory Bowel Disease (IBD) can affect the colon and/or rectum (Ulcerative colitis), or the small and large intestine (Crohn's Disease). The pathogenesis of these diseases is unclear, but they involve chronic inflammation of the affected tissues. Potential therapeutics include anti-IL-31Ra and/or OSMRb molecules, including, anti-IL-31Ra and/or OSMRb antibodies, other binding proteins, variants, fragments, chimeras, and other IL-31Ra and/or OSMRb antagonists. These molecules could serve as a valuable therapeutic to reduce inflammation and pathological effects in IBD and related diseases.

Ulcerative colitis (UC) is an inflammatory disease of the large intestine, commonly called the colon, characterized by inflammation and ulceration of the mucosa or innermost lining of the colon. This inflammation causes the colon to empty frequently, resulting in diarrhea. Symptoms include loosening of the stool and associated abdominal cramping, fever and weight loss. Although the exact cause of UC is unknown, recent research suggests that the body's natural defenses are operating against proteins in the body which the body thinks are foreign (an “autoimmune reaction”). Perhaps because they resemble bacterial proteins in the gut, these proteins may either instigate or stimulate the inflammatory process that begins to destroy the lining of the colon. As the lining of the colon is destroyed, ulcers form, releasing mucus, pus and blood. The disease usually begins in the rectal area and may eventually extend through the entire large bowel. Repeated episodes of inflammation lead to thickening of the wall of the intestine and rectum with scar tissue. Death of colon tissue or sepsis may occur with severe disease. The symptoms of ulcerative colitis vary in severity and their onset may be gradual or sudden. Attacks may be provoked by many factors, including respiratory infections or stress. Thus, the anti-IL-31 molecules of the present invention can be useful to treat and or detect UC.

Although there is currently no cure for UC available, treatments are focused on suppressing the abnormal inflammatory process in the colon lining. Treatments including corticosteroids immunosuppressives (eg. azathioprine, mercaptopurine, and methotrexate) and aminosalicytates are available to treat the disease. However, the long-term use of immunosuppressives such as corticosteroids and azathioprine can result in serious side effects including thinning of bones, cataracts, infection, and liver and bone marrow effects. In the patients in whom current therapies are not successful, surgery is an option. The surgery involves the removal of the entire colon and the rectum.

There are several animal models that can partially mimic chronic ulcerative colitis. The most widely used model is the 2,4,6-trinitrobenesulfonic acid/ethanol (TNBS) induced colitis model, which induces chronic inflammation and ulceration in the colon. When TNBS is introduced into the colon of susceptible mice via intra-rectal instillation, it induces T-cell mediated immune response in the colonic mucosa, in this case leading to a massive mucosal inflammation characterized by the dense infiltration of T-cells and macrophages throughout the entire wall of the large bowel. Moreover, this histopathologic picture is accompanied by the clinical picture of progressive weight loss (wasting), bloody diarrhea, rectal prolapse, and large bowel wall thickening (Neurath et al. Intern. Rev. Immunol 19:51-62, 2000).

Another colitis model uses dextran sulfate sodium (DSS), which induces an acute colitis manifested by bloody diarrhea, weight loss, shortening of the colon and mucosal ulceration with neutrophil infiltration. DSS-induced colitis is characterized histologically by infiltration of inflammatory cells into the lamina propria, with lymphoid hyperplasia, focal crypt damage, and epithelial ulceration. These changes are thought to develop due to a toxic effect of DSS on the epithelium and by phagocytosis of lamina propria cells and production of TNF-alpha and IFN-gamma. DSS is regarded as a T cell-independent model because it is observed in T cell-deficient animals such as SCID mice.

The administration of IL-31Ra and/or OSMRb antagonists or binding partners to these TNBS or DSS models can be used to measure the amelioration of symptoms and alter the course of gastrointestinal disease. IL-31 or may play a role in the inflammatory response and pain associated with colitis, and the neutralization of IL-31 activity by administrating antagonists is a potential therapeutic approach for IBD.

Irritable Bowel Syndrome is one of the most common conditions in the gastrointestinal clinic. Yet, diagnosis and treatment for IBS remain limited. As the expression of IL-31 and IL-31RA1 have been correlated with upregulation of Crohn's disease (See Example 5). IL-31Ra and/or OSMRb antagonists, including anti-IL-31Ra and/or OSMRb antibodies, other binding proteins, variants, fragments, chimeras, and other IL-31Ra and/or OSMRb antagonists are useful in reducing symptoms and treatment of the disease.

The administration of IL-31Ra and/or OSMRb antagonists or binding partners to a patient with IBD or IBS can be used to ameliorate symptoms and alter the course of gastrointestinal disease. IL-31 may play a role in the inflammatory response in colitis, and the neutralization of IL-31 activity by administrating antagonists is a potential therapeutic approach for IBD and/or IBS.

For disorders related to IBS and IBD, clinical signs of improved function include, but are not limited to, reduction in pain, cramping and sensitivity, reduction in diarrhea and improved stool consistency, reduced abdominal distension, and increased intestinal transit. Improvement can also be measured by a decrease in mean Crohn's Disease Activity Index (CDAI). See Best. W. et al., Gasttoenterology 70: 439-44, 1976. Additonally, improved function can be measured by a quality of life assessment as described by Irvine et al. (Irvine, E. et al., Gasttoenterology 106: 287-96, 1994.

Animal models of irritable bowel syndrome are described by Mayer and Collins. Gastroenterol. 122:2032-2048 (2002). These models can be divided into those that are mediated primarily by CNS-directed mechanisms (“Stress Memory” models) and those with primary gut-directed etiologies (“Pain Memory” and “Immune Memory” models). In one model, animals are surgically prepared with electrodes implanted on the proximal colon and striated muscles, and catheters implanted in lateral ventricles of the brain. Rectal distension is performed by inflation of a balloon rectally inserted, and the pressure eliciting a characteristic visceromotor response is measured. A test compound, such as IL-31Ra and/or OSMRb antagonist and/or variants or antagonists, is administered via the appropriate route (p.o., i.p., s.c., i.v., or i.m.) and at the appropriate time (i.e. ˜20 min, if i.p. or i.c.v.) prior to distention. Test compound is evaluated for its ability to affect colonic motility, abdominal contractions, and visceral pain.

Additionally, disorders associated with inflammation of the intestine can be treated with the IL-31Ra and/or OSMRb antagonists such as fragments, agonists and antagonists thereof described herein. For example, Irritable Bowel Syndrome (IBS) is characterized by a very broad spectrum of symptoms (pain; bouts of diarrhea and/or constipation; abnormal gastrointestinal motility). It is difficult to pinpoint the etiology, and may have components related to stress, genetics, and/or inflammation. Simiarly, the anti-IL-31Ra and/or OSMRb molecules of the present invention, including antibodies and binding partners, can be used to treat Inflammatory Bowel Disease, (including colitis and Crohn's disease). IBD is more serious than IBS, and is characterized by diarrhea, pain, and malnutrition. Patients with IBD often have increased risk of gastrointestinal cancer.

Gastrointestinal motor activity can be measured in a dog model as follows: Dogs are anesthetized and the abdominal cavity opened. Extraluminal force transducers (sensor to measure contraction) are sutured onto five (5) sites, i.e., the gastric antrum, 3 cm proximal to the pyloric ring, the duodenum, 5 cm distal to the pyloric ring, the jejunum, 70 cm distal to the pyloric ring, the ileum, 5 cm proximal to the ileum-colon junction, and the colon, 5 cm distal to the ileum-colon junction. The lead wires of these force transducers are taken out of the abdominal cavity and then brought out through a skin incision made between the scapulae, at which a connector is connected. After the operation, a jacket protector is placed on the dog to protect the connector. Measurement of the gastrointestinal motor activity is started two weeks after the operation. For ad libitum measurement, a telemeter (electrowave data transmitter) is connected with the connector to determine the contractive motility at each site of the gastrointestinal tract. The data is stored in a computer via a telemeter for analysis. A test compound, such as IL-31 antagonist is administered via the appropriate route (p.o., i.v., i.p., s.c., i.m.) at the appropriate time point to assess its ability to affect gastrointestinal motor activity. This can be performed in normal dogs or dogs in which gastroparesis/ileus has been induced. The above method is a modification of those in Yoshida. and Ito. J. Pharmacol. Experiment. Therap. 257, 781-787 (1991) and Furuta et al. Biol. Pharm. Bull. 25:103-1071 (2002).

IL-31 may be a trigger for reactivation of latent viral infections, such as varicella infection. In primary varicella zoster virus (VZV) infection, the T cells most likely to be infected by varicella zoster virus are CD4 positive memory T cells expressing CLA and CCR4. These are skin-homing T cells, which may enhance cell-associated viremia and the transport of infectious virus to the skin and DRG. These cells are also the primary producers of IL-31. Thus, IL-31 in primary VZV infection may contribute to the itch/pain involved in the skin lesions. Reactivation of latent virus in DRG induces VZV-specific T cell responses, which contribute to the neurogenic inflammation. Skin-homing T cells are most easily infected with VZV, and in vivo transfer of virus from T cells to DRG has been observed. Postherpetic neuralgia is one of the major complications of herpes zoster caused by the reactivation of varicella-zoster virus and is characterized by severe pain. See Sato-Takeda, M. et al., Anesthesiology. 2006 104(5):1063-9, herein incorporated by reference. This reference also teaches a mouse model of postherpetic pain, which corresponds to postherpetic neuralgia. Briefly, BALB/c mice (MHC haplotype: H-2), C57BL/6 mice (MHC haplotype: H-2), and BALB/b mice, a congenic BALB/c strain with H-2, are transdermally inoculated on the hind paw with Herpes simplex virus type I. Unilaterally zosteriform skin lesion and pain-related responses (acute herpetic pain) are caused, and some mice show pain-related responses (postherpetic pain) after the cure of skin lesions. Herpes simplex virus type I antigen and CD3-positive cells are immunostained in the dorsal root ganglion in the acute phase. See also Argoff, C. E., et al., J Pain Symptom Manage. 2004 October; 28(4):396-411, herein incorporated by reference. Antagonists to IL-31Ra and/or OSMRb can be used to limit or prevent reactivation of viral infections with varicella.

Mouse models for experimental allergic encephalomyelitis (EAE) has been used as a tool to investigate both the mechanisms of immune-mediated disease, and methods of potential therapeutic intervention. The model resembles human multiple sclerosis, and produces demyelination as a result of T-cell activation to neuroproteins such as myelin basic protein (MBP), or proteolipid protein (PLP). Inoculation with antigen leads to induction of CD4+, class II MHC-restricted T-cells (Th1). Changes in the protocol for EAE can produce acute, chronic-relapsing, or passive-transfer variants of the model (Weinberg et al., J. Immunol. 162:1818-26, 1999; Mijaba et al., Cell. Immunol. 186:94-102, 1999; and Glabinski, Meth. Enzym. 288:182-90, 1997). Administration of IL-31 antagonists or other soluble and fusion proteins may be useful to ameliorate symptoms and alter the course of disease.

Antagonists to IL-31-induced signal transduction in dorsal root gangion cells, such as anti-IL-31Ra and/or anti-OSMRb can be useful to treat pruritus uraemicus; pruritis from hepatitis, hepatic failure, or cholestasis; from scabies or athletes's foot; from pruritis associated with pregnancy; from pruritis in dualysis patients; and from pruritis from anaesthasia and psychological disorders as follows.

Pruritus uraemicus or renal itch is an often intolerable symptom of chronic renal insufficiency (Blachley J D, Blankenship D M, Menter A et al. Uremic pruritus: skin divalent ion content and response to ultraviolet phototherapy. Am J Kidney Dis 1985; 5: 237-41) being present in about 13% of the cases; secondary skin lesions due to scratching can be seen. It is even more common in patients undergoing peritoneal dialysis or hemodialysis (Murphy M, Carmichael A J. Renal itch. Clin Exp Dermatol 2000; 25: 103-6); it can be localized or generalized. Itching is not present in acute renal failure. The treatment of renal pruritus is based on intensive and efficient dialysis to remove pruritogenic substances from the blood, and on the use of non-complement-activating membranes. One can also use UV therapy, emollient ointments, activated charcoal, cholestyramine (4 grams twice a day), phosphate binding agents. Sometimes parathyroidectomy is necessary.

Pain antagonizes itch. See, for example, Ward, L. et al., Pain 64:129-138, 1996. As such a mediator of pain, such as an IL-31Ra and/or OSMRb antagonist can be used to treat pain associated with itch, thereby ameliorating not only the itch, or scratching behavior, but also the associated pain.

Pruritus is a well-recognized manifestation among patients with liver diseases and intrahepatic or posthepatic cholestasis. Hepatic diseases leading to pruritus include primary biliary cirrhosis, B and C viral hepatitis, primary sclerosing cholangitis, carcinoma of bile ducts, alcoholic cirrhosis, autoimmune hepatitis and others. The pruritus is generalized and more intense on hands, feet and around tight-fitting clothes, while face, neck and genital area are rarely involved.

Generalized pruritus is present in 1-8% of pregnant women. Pruritus gravidarum can be differentiated from pruritic dermatoses in pregnancy, such as pemphigoid gestationis (herpes gestationis), papular and pruritic dermatosis of pregnancy and others. Pruritus gravidarum manifests without any rash mostly in the third trimester of pregnancy, but it may also appear earlier, firstly on the abdomen and then becomes generalized. This symptom usually tends to be worse at night and disappears after delivery (within 1-4 weeks). Probably it is associated with intrahepatic cholestasis, as there is an increase of gamma GT and alkaline phosphatase, and sometimes also of direct bilirubin level in these patients. Pruritus is more frequent in multiple pregnancies and can recur in subsequent pregnancies or during the use of oral contraceptives. Additonally, pruritic urticarial papulas and plaques of pregnancy (PUPP), the most common dermatosis associated with pregnancy, does not respond to antihistamines and often persists beyond parturition.

Some hematological disorders are known to be associated with pruritus. In polycythemia rubra vera with overproduction of all three hematopoietic cell lines, patients typically experience severe itch located on the trunk, but sparing the face, hands and feet, a few minutes after contact with warm water. Water-induced itching (aquagenic pruritus, or bath itch) can be present in 70% of the patients. The itch can last for about 15 minutes to one hour, and be so severe that the patients refuse to bathe. In the last decades pruritus has been described in patients with graft versus host reactions after bone marrow transplantation.

Chronic delivery of IL-31 induces pruritis and alopecia in mice followed by the development of skin lesions resembling dermatitis suggesting that IL-31 may induce itching. See See Dillon S. R., et al., Nat Immunol: 5, 752 (2004). The involvement of IL-31 was tested in induction of the itch response by two methods as shown in Example 2: (i) capsaicin treatment of IL-31-treated mice and (ii) IL-31 treatment of Tac1 knockout mice, which have significantly reduced nociceptive pain responses because of lack of expression of neuropeptides. In addition, whether neutralization of IL-31 in IL-31 treated mice could prevent pruritis and alopecia was tested in Example 2.

NC/Nga Mice spontaneously develop AD-like lesions that parallel human AD in many aspects, including clinical course and signs, histophathology and immunopathology when housed in non-specified pathogen-free (non-SPF) conditions at around 6-8 weeks of age. In contrast, NC/Nga mice kept under SPF conditions do not develop skin lesions. However, onset of spontaneous skin lesions and scratching behaviour can be synchronized in NC/Nga mice housed in a SPF facility by weekly intradermal injection of crude dust mite antigen. See Matsuoka H., et al., Allergy: 58, 139 (2003). Therefore, the development of AD in NC/Nga is a useful model for the evaluation of novel therapeutics for the treatment of AD.

In addition to the NC/Nga model of spontaneous AD, epicutaneous sensitization of mice using OVA can also be used as a model to induce antigen-dependent epidermal and dermal thickening with a mononuclear infiltrate in skin of sensitized mice. This usually coincides with elevated serum levels of total and specific IgE, however no skin barrier dysfunction or pruritus normally occurs in this model. See Spergel J. M., et al., J Clin Invest, 101: 1614, (1998). This protocol can be modified in order to induce skin barrier disregulation and pruritis by sensitizing DO11.10 OVA TCR transgenic mice with OVA. Increasing the number of antigen-specific T cells that could recognize the sensitizing antigen may increase the level of inflammation in the skin to induce visible scratching behaviour and lichenification/scaling of the skin.

Both the NC/Nga spontaneous AD model and the OVA epicutaneous DO11.10 model can be used to measure expression of IL-31 and IL-31RA in AD, as well as the ability of the antagonists described herein to inhibit, reduce, or neutralize the effects of IL-31. The antagonists described herein are useful to inhibit scratching associated with dermatitis and pruritic diseases including atopic dermatitis, prurigo nodularis, and eczema. In AD, the scratching behavior provoked by intensely itchy skin is believed to aggravate disease by breaking down skin barrier functions and activating keratinocytes, leading to chemokine production and increased inflammation. Many clinicians view AD as a self-propagating cycle, since lesions formed by frequent scratching are subject to infection and further antigen stimulation. The fact that patients with near total involvement of body surface area may have unaffected skin in regions that are hard to scratch lends credence to this hypothesis. By preventing pruritis, administration of antagonists of IL-31Ra and/or OSMRb can be effective in treating pruritic disease by decreasing IL-31-induced keratinocyte activation and neurological stimulation, thus breaking the link between inflammation and pruritis. The reduction in pruritis could also decrease secretion of neurostimulatory factors and reduce the inflammation and excoriations associated with constant scratching, leading to an improvement in disease scores and/or a longer duration between disease flares. An inhibition, reduction, or prevention of scratching, alone, can be effective in treating pruritic diseases including, but not limited to, atopic dermatitis, prurigo nodularis, and eczema, since cessation of scratching will stop progression of dermatitis, the development of which is dependent on scratching.

As used herein, the term “antibodies” includes polyclonal antibodies, affinity-purified polyclonal antibodies, monoclonal antibodies, and antigen-binding fragments, such as F(ab′)2 and Fab proteolytic fragments. Genetically engineered intact antibodies or fragments, such as chimeric antibodies, Fv fragments, single chain antibodies and the like, as well as synthetic antigen-binding peptides and polypeptides, are also included. Non-human antibodies may be humanized by grafting non-human CDRs onto human framework and constant regions, or by incorporating the entire non-human variable domains (optionally “cloaking” them with a human-like surface by replacement of exposed residues, wherein the result is a “veneered” antibody). In some instances, humanized antibodies may retain non-human residues within the human variable region framework domains to enhance proper binding characteristics. Through humanizing antibodies, biological half-life may be increased, and the potential for adverse immune reactions upon administration to humans is reduced. Moreover, human antibodies can be produced in transgenic, non-human animals that have been engineered to contain human immunoglobulin genes as disclosed in WIPO Publication No. WO 98/24893. It is preferred that the endogenous immunoglobulin genes in these animals be inactivated or eliminated, such as by homologous recombination.

Antibodies are considered to be specifically binding if: 1) they exhibit a threshold level of binding activity, and 2) they do not significantly cross-react with related polypeptide molecules. A threshold level of binding is determined if anti-IL-31 antibodies herein bind to a IL-31 polypeptide, peptide or epitope with an affinity at least 10-fold greater than the binding affinity to control (non-IL-31) polypeptide. It is preferred that the antibodies exhibit a binding affinity (Ka) of 106 M-1 or greater, preferably 107 M-1 or greater, more preferably 108 M-1 or greater, and most preferably 109 M-1 or greater. The binding affinity of an antibody can be readily determined by one of ordinary skill in the art, for example, by Scatchard analysis (Scatchard, G., Ann. NY Acad. Sci. 51: 660-672, 1949).

Whether anti-IL-31 antibodies do not significantly cross-react with related polypeptide molecules is shown, for example, by the antibody detecting IL-31 polypeptide but not known related polypeptides using a standard Western blot analysis (Ausubel et al., ibid.). Examples of known related polypeptides are those disclosed in the prior art, such as known orthologs, and paralogs, and similar known members of a protein family. Screening can also be done using non-human IL-31, and IL-31 mutant polypeptides. Moreover, antibodies can be “screened against” known related polypeptides, to isolate a population that specifically binds to the IL-31 polypeptides. For example, antibodies raised to IL-31 are adsorbed to related polypeptides adhered to insoluble matrix; antibodies specific to IL-31 will flow through the matrix under the proper buffer conditions. Screening allows isolation of polyclonal and monoclonal antibodies non-crossreactive to known closely related polypeptides (Antibodies: A Laboratory Manual, Harlow and Lane (eds.), Cold Spring Harbor Laboratory Press, 1988; Current Protocols in Immunology, Cooligan, et al. (eds.), National Institutes of Health, John Wiley and Sons, Inc., 1995). Screening and isolation of specific antibodies is well known in the art. See, Fundamental Immunology, Paul (eds.), Raven Press, 1993; Getzoff et al., Adv. in Immunol. 43: 1-98, 1988; Monoclonal Antibodies: Principles and Practice, Goding, J. W. (eds.), Academic Press Ltd., 1996; Benjamin et al., Ann. Rev. Immunol 2: 67-101, 1984. Specifically binding anti-IL-31 antibodies can be detected by a number of methods in the art, and disclosed below.

Preparation of monoclonal antibodies is well known to one skilled in the art. The purified mature recombinant human IL-31 polypeptide (amino acid residues 27 (Leu) to 167 (Thr) of SEQ ID NO:2) or the mouse ortholog, produced from expression systems can be used to generate monoclonal antibodies.

The effect of administering the antagonists of IL-31 mediated signal transduction can be measured in vivo by a reduction, inhibition, prevention, minimization, neutralization of inflammation, of skin or dermal thickening, of recruitment of lymphocytes, and acanthosis, for example, and other symptoms or composites of symptoms, such as the Eczema Area and Severity Index (EASI), that are evident to one skilled in the art. Additional effects could include a change or decrease in the production of cytokines or chemokines by lesional skin, reduction in an atopy patch test score, and decrease in release of soluble factors such as cytokines, chemokines or neuropeptides, as measured by intradermal microdialysis or other methods. Assessments of degree of itch or pain can be measured using clinically approved instruments or tools such as the Visual Analogue Scale. Frequency of scratching can be monitored by limb movement meters, piezoelectric transducer devices attached to the fingernails, or time-lapse infrared photography or videography of nocturnal scratching in patients. Other methods for assessing a decrease in pain or itch are evident to one skilled in the art.

Monoclonal antibodies purified from tissue culture media are characterized for their utility in an ELISA for the quantitative determination of recombinant and native human IL-31. The antibodies are selected and a quantitative assay is developed.

Monoclonal antibodies purified from tissue culture media are characterized for their ability to block or reduce the receptor binding activity (“neutralization assay”) of purified recombinant huIL-31 on neural cells expressing the IL-31Ra and OSMRb. A number of “neutralizing” monoclonal antibodies are identified in this manner. Hybridomas expressing the neutralizing monoclonal antibodies to human IL-31 described can then be deposited with the American Type Tissue Culture Collection (ATCC; Manassas Va.) patent depository as original deposits under the Budapest Treaty.

Monoclonal antibodies in tissue culture media are characterized for their ability to block or reduce receptor binding when grown in the presence of the purified recombinant proteins human IL-31.

Bidnding affinity of the monoclonal antibodies can be generated. Goat-anti-Rat IgG-Fc gamma specific Antibody (Jackson) is immobilized onto a CM5 Biacore chip. The assay is optimized to bind each mAb onto the anti-Rat capture surface and then a concentration series of IL-31 is injected across the mAb to see association (Ka) and dissociation (Kd). After each run, the surface is regenerated back to the anti-Rat Antibody with 2 injections of 20 mM HCl. Data is generated for each and evaluation software (BIAevaluation software version 3.2, Pharmacia BIAcore, Uppsala, Sweden) is used to assess the kinetics of the anti-IL-31 antibody binding to the IL-31 protein

Biochemical confirmation that the target molecule, IL-31, recognized by the putative anti-IL-31 mAbs is indeed IL-31 are performed by standard immunoprecipitation followed by SDS-PAGE analysis or western blotting procedures, both employing soluble membrane preparations from IL-31 transfected versus untransfected Baf3 cells. The mAbs are tested for their ability to specifically immunoprecipitate or western blot the soluble IL-31-muFc protein.

IL-31Ra and/or OSMRb antagonists generated by the methods described herein can be tested for neutralization, inhibition, reduction, antagonizaiton by a variety of methods. In addition neutralization can be tested by measuring a decrease in the production of pro-inflammatory chemokines such as TARC and MDC from keratinocyte cultures in the presence of ligand and the monoclonal antibody. Other biomarkers, such as MCP-1, MIP1a, TARC, MCP-1, MDC, IL-6, IL-8, 1-309, SCYA19, MPIF-1, TECK, MIP-1b, SCYB13, GROa/MGSA, CTACK, SCCA1/Serpin B3, TSLP, and NT-4 may also be used. Neutralization can also be measured by the in vivo models described herein.

The bioactive antagonists or antibody conjugates described herein can be delivered intravenously, intraarterially or intraductally, subcutaneously, topically, or may be introduced locally at the intended site of action.

The antagonists of the present invention can be measured for their ability to bind the IL-31 ligand as determined by any of the in vivo models described herein, including but not limited to the NcNga model, the Ova epicutaneous model, the chronic hypersensitivity model, the chronic hapten model, the calcium flux model, the allodynia model.

Additonal models to measure the inhibitory effects of the anti-IL-31Ra and/or OSMRb antagonists are known to one skilled in the art and described herein are described by Umeuchi, H. et al., European Journal of Pharmacology, 518: 133-139, 2005; and by Yoo, J. et al., J. Experimental Medicine, 202:541-549, 2005.

Mouse models to measure neurogenic inflammation are known in the art. See, for example, Sweitzer, S. M., et al., J. Neuroimmunology 125: 82-93; 2002, and Honore, P., et al., Neuroscience, (98): 585-598, 2000. See also, Yonehara, N. and Yoshimura M., Pain, 2001 (92/1-2): pp. 259-265).

Within aspects of the invention, the invention provides methods of treating inflammation in neuronal tissue of a mammal; methods of treating pain in a mammal; methods of antagonizing IL-31 induced signal transduction is dorsal root ganglion cells; methods for treating symptoms associated with burn; methods for treating symptoms associated with viral infection and for preventing reactivation of viral infection; and methods of treating pain associated with Inflammatory Bowel Disease. Within an embodiment, the Inflammatory Bowel Disease is Crohn's Disease.

Within embodiments of these aspects, the invention provides, comprising admixing neuronal tissue with an IL-31Ra and/or OSMRb antagonist, wherein the inflammation, pain, dorsal root ganglion signal transduction, viral infection or reactivation, or burn tissue, or pain associated with Inflammatory Bowel Disease is reduced, limited, prevented, minimized or neutralized.

Within other embodiments, the IL-31Ra and/or OSMRb antagonist binds a polypeptide comprising an amino acid sequence as shown in SEQ ID NO: 2 from residue 27 to residue 164. Within other embodiments, the antagonist is selected from: anti-idiotype antibodies; antibody fragments; chimeric antibodies; and humanized antibodies. Within another embodiment the antagonist a soluble receptor. Within other embodiments the soluble receptor comprises at least one subunit of IL-31Ra.

Within other embodiments the neuronal tissue comprises dorsal root ganglion or spinal cord tissues.

EXAMPLES Example 1 In Situ Hybridization for IL-31RA, IL-31, and pOSMRb in Neuronal Tissues

Five human brain tissue samples and a spinal cord sample all from the same individual, and a dorsal root ganglia (DRG) from a different patient were analyzed in this study.

Probes used were probes to IL-31RA, IL-31, and OSMRbeta.

Results are shown in Table 1:

TABLE 1 ISH analysis results: Tissue/probe IL-331RA pOSMRb IL-31 brain frontal lobe − − − brain hippocampus − − − brain parietal lobe − − − brain temporal lobe, − − − brain hypothalamus − +/− − spinal cord + + − DRG + + −

Brain sections: There was no detectable amount of signal in all regions of the brain for all three probes. There was inconsistent staining of pOSMRb in a subset of neurons in the hypothalamus. The inconsistency may cause by very low level of pOSMRb expression that is around the level of detection.

Spinal cord: There was positive staining in one region of the spinal cord. The information about the possible location or orientation of the spinal cord section was unavailable. The signal appears to be in the anterior (ventral) portion of the spinal cord. The opposite side/region (also anterior) was negative. The positive signal appears to confine in a subset of larger neurons. Both IL-31RA and pOSMRb showed similar expression patterns in this area. IL-31 was negative.

Dorsal Root Ganglion (DRG): A subset of unipolar neurons in the DRG was positive for both IL-31RA and pOSMRb. Small satellite cells were negative. IL-31 was negative in all cells including neurons.

Thusm an IL-31 antagonist can be useful to ameliorate symptoms associated with neurogenic stimulation and neurogenic stimulation. As such the IL-31 antagonists, can be used to treat inflammation and pain associate with neural cell stimulation, such as dorsal root ganglion stimulation, and can be measured as a reduction, limitation, minimization, prevention, or neutralization of pain and inflammation.

Example 2 IL-31 Involvement in Induction of the Itch Resonse

A. Methods I (Capsaicin Treatment of IL-31 Treated Mice)

Ten week old BALB/c animals (CRL) were anaesthetized and injected with a long-lasting analgesic agent, bupranorphine hydrochloride, subcutaneously at 0.1 mg/kg before injection of 0.25 ml of 4 mg/ml solution of capsaicin in 10% ethanol+10% Tween-80 in saline subcutaneously into scruff of neck. Animals were kept anaesthetized for at least 30 min following neurotoxin treatment. Forty-eight hours later, 14-day osmotic pumps were implanted subcutaneously for continuous delivery of 20 ug/day of IL-31 for 14 days. Mice were monitored daily for 6 days for alopecia and pruritis using the following criteria: 0=no scratching, animal appears normal, 1=thinning of coat in small areas, scratching noted, 2=minor hair loss (small patches), scratching, 3=moderate hair loss, scratching, and 4=severe hair loss, excessive scratching.

Results demonstrated that while non-capsaicin-treated mice showed a mean scratch/hairloss score of 2.625 following three days of IL-31 delivery, capsaicin-treated mice showed a significantly lower score of 1. Thus mice treated with capsaicin prior to IL-31 delivery showed both a delay in incidence of scratching and hairloss and a lower score in the intensity of scratching and hairloss over the six days of the experiment. These data suggest that IL-31 does induce some neuronal component that contributes to the alopecia and pruritis induced by IL-31. Therefore, neutralization of IL-31 may decrease the incidence and intensity of itch, and therefore dermatitis, in patients suffering from skin disorders that involve itch.

B. Methods II

Mice that are homozygous null for the Tac1 gene express no detectible substance P or neurokinin A. These mice have significantly reduced nociceptive pain responses to moderate to intense stimuli and are therefore a useful tool for studying the contribution of tachykinin peptides to pain/itch processing and inflammatory disease states. Twelve week old, Tac1 knockout mice were implanted with 14-day osmotic pumps delivering 1 ug/day of IL-31 protein and observed daily for alopecia and pruritis using the following criteria: 0=no scratching, animal appears normal, 1=thinning of coat in small areas, scratching noted, 2=minor hair loss (small patches), scratching, 3=moderate hair loss, scratching, and 4=severe hair loss, excessive scratching.

Results of this study show that Tac1 deficient mice were less susceptible to IL-31 induced scratching/hairloss compared to wildtype control mice. While 100% (10/10) of wildtype mice had developed evidence of scratching and hairloss by day 6 of IL-31 treatment, only 33.3% (2/6) Tac1 deficient mice were showing signs of scratching and hairloss at the same time-point. These data show that IL-31 induces a neuronal component that contributes to the scratch/hairloss phenotype in IL-31-treated mice and neutralization of IL-31 may decrease the incidence and intensity of scratching in the context of dermatitis.

C. Methods III (Administration of IL-31 Neutralizing Antibody)

Normal female BALB/c mice (CRL) approximately 8 to 12 weeks old were implanted subcutaneously with 14-day osmotic pumps (Alzet, #2002) delivering 1 ug/day mIL-31. Groups of mice received intraperitoneal (i.p.) injections of rat anti-mouse IL-31 monoclonal antibody 10 mg/kg (200 ug/mouse) twice weekly starting 1 week prior to IL-31 delivery. Control groups of mice received i.p. injections of vehicle (PBS/0.1% BSA) with the identical dosing schedules. Mice were scored daily for alopecia and pruritis using the following criteria: 0=no scratching, animal appears normal, 1=thinning of coat in small areas, scratching noted, 2=minor hair loss (small patches), scratching, 3=moderate hair loss, scratching, and 4=severe hair loss, excessive scratching.

In all experiments, mice treated with rat anti-mIL-31 mAb had a delay in onset of symptoms of approximately 5 to 7 days and a lower overall score for alopecia and pruritis. All groups of mAb treated mice (regardless of dose frequency or concentration) developed alopecia and pruritis similar to control mice by 13 day of the study. These data suggest that neutralization of IL-31 can delay the onset of the scratch/hairloss response induced by IL-31.

Example 3 IL-31RA/OSMRbeta Receptor Luciferase Assay

The KZ134 plasmid was constructed with complementary oligonucleotides that contain STAT transcription factor binding elements from 4 genes, which includes a modified c-fos Sis inducible element (m67SIE, or hSIE) (Sadowski, H. et al., Science 261:1739-1744, 1993), the p21 SIE1 from the p21 WAF1 gene (Chin, Y. et al., Science 272:719-722, 1996), the mammary gland response element of the β-casein gene (Schmitt-Ney, M. et al., Mol. Cell. Biol. 11:3745-3755, 1991), and a STAT inducible element of the Fcg RI gene, (Seidel, H. et al., Proc. Natl. Acad. Sci. 92:3041-3045, 1995). These oligonucleotides contain Asp718-XhoI compatible ends and were ligated, using standard methods, into a recipient firefly luciferase reporter vector with a c-fos promoter (Poulsen, L. K. et al., J. Biol. Chem. 273:6229-6232, 1998) digested with the same enzymes and containing a neomycin selectable marker. The KZ134 plasmid was used to stably transfect BaF3 cells, using standard transfection and selection methods, to make the BaF3/KZ134 cell line.

A stable BaF3/KZ134 indicator cell line, expressing the full-length IL-31RA or IL-31RA/OSMRbeta receptor was constructed. Clones were diluted, plated and selected using standard techniques. Clones were screened by luciferase assay (see B, below) using the human IL-31 conditioned media or purified IL-31 protein as an inducer. Clones with the highest luciferase response (via STAT luciferase) and the lowest background were selected. Stable transfectant cell lines were selected. The cell lines were called BaF3/KZ134/IL-31RA or BaF3/KZ134/IL-31RA/OSMRbeta depending on the receptors transfected into the cell line.

Similarly, BHK cell lines were also constructed using the method described herein, and were used in luciferase assays described herein. The cell lines were called BHK/KZ134/IL-31RA or BHK/KZ134/IL-31RA/OSMRbeta depending on the receptors transfected into the cell line.

BaF3/KZ134/IL-31RA and BaF3/KZ134/IL-31RA/OSMRbeta cells were spun down and washed in mIL-3 free media. The cells were spun and washed 3 times to ensure removal of mIL-3. Cells were then counted in a hemacytometer. Cells were plated in a 96-well format at about 30,000 cells per well in a volume of 100 ml per well using the mIL-3 free media. The same procedure was used for untransfected BaF3/KZ134 cells for use as a control in the subsequent assay. BHK/KZ134/IL-31RA or BHK/KZ134/IL-31RA/OSMRbeta cells were plated in a 96-well format at 15,000 cells per well in 100 μl media. Parental BHK/KZ134 cells were used as a control.

STAT activation of the BaF3/KZ134/IL-31RA, BaF3/KZ134/IL-31RA/OSMRbeta, BHK/KZ134/IL-31RA, or BHK/KZ134/IL-31RA/OSMRbeta cells is assessed using conditioned media or purified protein. One hundred microliters of the diluted conditioned media or protein is added to the BaF3/KZ134/IL-31RA, BaF3/KZ134/IL-31RA/OSMRb eta, BHK/KZ134/IL-31RA, or BHK/KZ134/IL-31RA/OSMRbeta cells. The assay using the conditioned media is done in parallel on untransfected BaF3/KZ134 or BHK/KZ134 cells as a control. The total assay volume is 200 μl. The assay plates are incubated at 37° C., 5% CO₂ for 24 hours at which time the BaF3 cells are pelleted by centrifugation at 2000 rpm for 10 min., and the media is aspirated and 25 μl of lysis buffer (Promega) is added. For the BHK cell lines, the centrifugation step is not necessary as the cells are adherant. After 10 minutes at room temperature, the plates are measured for activation of the STAT reporter construct by reading them on a luminometer (Labsystems Luminoskan, model RS) which added 40 μl of luciferase assay substrate (Promega) at a five second integration.

Example 4 Luciferase Assay on Human Transformed Epithelial Cell Lines Via Transient Infection with an Adenoviral STAT/SRE Reporter Gene

Inhibition, reduction, and/or neutralization of IL-31 activity can be measured by the luciferase assay. For example, human transformed cell lines can be seeded in 96-well flat-bottom plates at 10,000 cell/well in regular growth media as specified for each cell type. The following day, the cells are infected with an adenovirus reporter construct, KZ136, at a multiplicity of infection of 5000. The KZ136 reporter contains the STAT elements in addition to a serum response element. The total volume is 100 ul/well using DMEM supplemented with 2 mM L-glutamine (GibcoBRL), 1 mM Sodium Pyruvate (GibcoBRL) and 1× Insulin-Transferrin-Selenium supplement (GibcoBRL) (hereinafter referred to as serum-free media). Cells are cultured overnight.

The following day, the media is removed and replaced with 100 μl of induction media. The induction media is human IL-31 diluted in serum-free media at 100 ng/ml, 50 ng/ml, 25 ng/ml, 12.5 ng/ml, 6.25 ng/ml, 3.125 ng/ml and 1.56 ng/ml. A positive control of 20% FBS is used to validate the assay and to ensure the infection by adenovirus is successful. The cells are induced for 5 hours at which time the media is aspirated. The cells are then washed in 50 μl/well of PBS, and subsequently lysed in 30 μl/well of 1× cell lysis buffer (Promega). After a 10-minute incubation at room temperature, 25 μl/well of lysate is transferred to opaque white 96-well plates. The plates are then read on the Luminometer using 5-second integration with 40 μl/well injection of luciferase substrate (Promega).

Example 5 IL-31 Analysis in Colon Tissues from Inflammatory Bowel Disease

A) IL-31 Immunohistochemistry:

A polyclonal antibody (rabbit anti-human IL-31 CEE, affinity purified to 1.0 mg/ml) was used to detect human IL-31 in gastrointestinal tissues from inflammatory bowel disease patients via an ABC-elite based detection system. Normal Rabbit Serum, Protein A purified to 1.66 mg/ml was used as a negative control using the same protocol and antibody concentrations.

The protocol was as follows: ABC-HRP Elite (Vector Laboratories, PK-6100); Target Retrieval (ph 9) for 20′ steam, 20′ cooling to RT; Protein Block for 30′; Primary Ab (1:1,000-2,500) for 60′; Secondary Ab (Bi:ant-Rabbit) for 45′; ABC-HRP complex for 45′; and DAB substrate as recommended.

In this study, a total of 19 individual GI tissues were analyzed with the rabbit anti-human IL-31 polyclonal antibody. In this group, there are five colon samples from normal tissue adjacent to IBD or cancer tissues. Nine samples were diagnosed with Crohn's disease and five with ulcerative colitis. Overall, it appears there are more cells positive in the Crohn's samples than the normal tissues adjacent to the IBD or cancer tissues or ulcerative colitits tissues. The predominate cells with signal in the Crohn's samples are located in the laminar propria and submucosa, with infiltrating cells showing signal between the smooth muscle bundles. In granulomas, many larger cells in the nodule center are positive, however the cortex of these nodules, and Peyers patches appear negative. The epithelium of intestinal glands is occasionally positive. In ulcerative colitis samples, there are a small number of scattered cells in the submucosa and infiltrating cells between smooth muscle bundles are positive. The percentage of positive cells in ulcerative colitis samples is less than that of Crohn's, but similar, or slightly higher than that of “normal” samples. Cells in the laminar propria of ulcerative colitis are mostly negative. In summary, this study demonstrates that IL31 is upregulated in Crohn's GI samples. It appears that in this study, IL31 shows similar expression profiles in Ulcerative colitis samples and “Normal” controls.

B) IL-31 In Situ Hybridization:

A subset of the tissues was also analyzed using in situ hybridization (ISH). In ISH, IL-31 mRNA was observed in a few infiltrating cells in the submucosa and adipose tissues. Using IHC, we observed that IL31 protein stained positive in the previously mentioned cell population as well as in cells in the laminar propria and granuloma centers. The difference between these two assays could be explained by assay sensitivity.

Example 6 IL-31Ra Analysis in Colon Tissues from Inflammatory Bowel Disease

A) IL-31Ra Immunohistochemistry:

A polyclonal antibody (rabbit anti-human IL-31RA (version 4) CEE, affinity purified to 1.33 mg/ml) was used to detect human IL-31RA in gastrointestinal tissues from inflammatory bowel disease patients via an ABC-elite based detection system. Normal Rabbit Serum, Protein A purified to 1.66 mg/ml was used as a negative control using the same protocol and antibody concentrations. The rabbit anti-human IL-31RA (version 4) antibody was used at 1:2000 (665 ng/ml).

The protocol was as follows: ABC-HRP Elite (Vector Laboratories, PK-6100); Target Retrieval (ph 9) for 20′ steam, 20′ cooling to RT; Protein Block for 30′; Primary Ab (1:2,000) for 60′; Secondary Ab for 45′; ABC-HRP complex for 45′; and DAB+Dako Cytomation for 10′.

In this study, a total of 19 individual GI tissues were analyzed using the rabbit anti-human IL-31RA (version 4) CEE antibody. In this group, there are about five colon samples from normal tissue adjacent to IBD or cancer tissues. Nine samples were diagnosed with Crohn's disease and five with ulcerative colitis. Overall, it appears there are more cells positive in the Crohn's samples than normal tissue adjacent to IBD or cancer tissues or ulcerative colitis tissues. The positive cells in Crohn's are primarily located in the connective tissues of submucosa. Granulomas nodules are negative. Occasionally there is weak epithelium signal in the Crohn's samples. There was no detectable signal in the ulcerative colitis (UC) samples. A few cells in the submucosa were stained positive by IHC for the IL31RA protein.

B) IL-31Ra In Situ Hybridization:

In a previous study five tissues were studied using ISH, three of which were Crohn's colons. In these Crohn's tissues, IL31RA mRNA was significantly upregulated compared to their normal counterparts, and the signal was localized to the cortex of granuloma nodules and many infiltrating cells in the connective tissues of submucosa and adipose tissue areas. Possible reasons for the discrepancy between IHC and in situ analysis includes transient mRNA expression, protein process time, IL31RA protein stability, and/or sensitivity differences between the two assays.

Example 7 DSS-Induced Colitis Studies in EμLck IL-31 Transgenic Mice

EμLck IL-31 transgenic and non-transgenic littermate control mice were tested in a dextran sulfate sodium (DSS)-induced model of mucosal inflammation to look for potential differences in disease susceptibility and severity. Normal mice given 2-3% DSS in drinking water develop symptoms and pathology that mimic human inflammatory bowel disease (See, Strober, Fuss and Blumberg, Annu. Rev. Immunol. 2002). Mechanistically, DSS disrupts the mucosal epithelial barrier of the large intestine, which causes subsequent inflammation. As a result of this inflammation, DSS treated mice lose body weight and develop diarrhea. Mice are monitored for severity of colitis using a disease activity index (DAI), which is a cumulative score based on body weight, stool consistency and blood present in stool. DSS can be used to induce acute or chronic forms of colitis. Acute colitis is induced via delivery of DSS (2% or 3% in our studies) in drinking water from day 0 to day 7, while chronic colitis is induced via delivery of DSS in the drinking water for 5 days followed by a recovery phase of 7 to 12 days, before repeating the DSS treatment.

Four studies in the EμLck IL-31 transgenic mice were performed. Regardless of whether the acute or chronic model of DSS was used, the EμLck IL-31 transgenic mice lost more body weight earlier when compared with littermate control mice. In fact, in 3 of 4 studies the IL-31 transgenic mice demonstrated significantly more weight loss compared to controls (p<0.001, p=0.011). Additionally, transgenic mice had significantly shorter colons compared to wildtype controls (p<0.05). The DAI score was significantly higher in IL-31 transgenic mice compared to non-transgenic controls in a chronic colitis study (p<0.001).

To determine if systemic delivery of IL-31 could influence the development of DSS-induced colitis in normal non-transgenic mice, we implanted animals with osmotic pumps delivering a daily dose of IL-31 or vehicle (PBS, 0.1% BSA) prior to DSS treatment. In one study, N3 generation, non-transgenic mice (B6C3F2×57BL/6) were implanted with pumps subcutaneously which delivered either 20 μg/day IL-31 or vehicle during the course of the DSS administration. There were no differences in weight loss, DAI score, or colon length between the IL-31 treated mice versus vehicle treated mice. A similar pump delivery study was also performed in normal C57BL/6 mice; mice were implanted with pumps that delivered 10 mg/day IL-31 or vehicle and given 2% DSS in the acute regime. Again, there were no differences between mice in any of the DSS-colitis parameters whether implanted with IL-31 or vehicle-delivering pumps. Finally, a 2% DSS-acute colitis study was performed in IL-31RA deficient (IL-31RA−/−) mice. Again, there were no differences in body weight loss, DAI score or colon length between IL-31RA deficient mice and wildtype controls.

In summary, IL-31 does not appear to directly effect mucosal inflammation induced by DSS since systemic delivery of IL-31 to normal mice in acute colitis studies had no effect on disease outcome. IL-31 transgenic animals may be more susceptible to DSS-induced colitis as a result of stress caused by the transgenic phenotype. However, EμLck IL-31 transgenic mice have increased numbers of activated CD4+ and CD8+ T cells in the peripheral lymph nodes (Dillon, et al, 2004) and the increased susceptibility to DSS-induced colitis observed in the EμLck IL-31 transgenic mice may be a consequence of the presence of these activated lymphocytes.

Example 8 Effects of Anti-IL31 Treatment by Sampling Dermal Interstitial Fluid with Microdialysis

Microdialysis can be used with the molecules of the present invention to measure direct analysis of bioavailability and the distribution of antibodies in the skin. Microdialysis is use to collect and analyze the intercellular fluid. The antibody in the interstitial fluid can be determined using a species-specific anti-IgG cross-linked to a luminex bead. Further, an evaluation of free to IgG-bound IL31 is done using an anti-IL31 rather than anti-IgG as the secondary antibody. 2. Proinflammatory cytokines and chemokines produced by IL31 activation of keratinocytes and/or dorsal root ganglion is assayed. See British J. Dermatology 142(6); 1114-1120, (2000); J. Neurol. Neurosurg. Psychiatry 73; 299-302, (2002); Am J. Physiol Heart Circ. Physiol 286; 108-112, (2004); Neuroscience Letters 230; 117-120, (1997); and AAPS J. 7(3); E686-E692, (2005). See also Steinhoff, M., et al., J. Neuroscience, 23 (15): 6176-6180, 2003.

Microdialysis probes are supplied by TSE Systems (Midland, Mich.). The probe is T-shaped and consists of a 3000 kDa membrane 0.3 mm OD by 4 mm L attached to a 15 mm stem. The inlet and outlet are connected to 0.12 mm ID peek tubing. The ex vivo analysis is performed using tubing lengths identical to that used for in vivo analysis. HMWCO probes are run with a push/pull pump system to minimize outward (into the interstitial) flow. However a push only (Harvard PHD 2000) is also used. Fluid loss due to Δp and ΔΠ is determined at various flow rates. The efficiency (Ed) of the membrane is determined at various flow rates using known quantities of IgG in a mixing chamber to eliminate non-membrane (external) diffusion. The Ed of mouse IgG and mouse hemoglobin is determined and serve as in vivo controls. Quantitation is by goat anti-Rat-IgG coupled to Luminex beads and capture is reported with rabbit or donkey biotin-anti-rat IgG to reduce non-specific reactivity. Assays for mouse IgG and Hemoglobin is developed for controls in the in vivo studies. Bead coupling will be performed using a standard kit and protocol.

Treatment of mice and rats with cytokines by osmotic pump, ID or through a microdialysis fiber is used. Antibody is injected by IV. The probe is UV sterilized. The microdialysis probe is inserted and blood an analytes are sampled. Quantification of IgG transport from circulation into the skin is measured using membrane parameters determined ex vivo, antibody permeability and the perfusion rate are estimated.

The following steps are performed using one time point per animal pair and a sufficient number of time points to estimate circulating antibody levels and diffusion into the dermis/epidermis over time: i) a microdialysis membrane is inserted into the skin and a preliminary sample withdrawn at a rate determined by the ex vivo analysis. This control sample determines the baseline reactivity of the permeate fluid; 2) Rat anti-IL31 antibody is introduced by IV tail injection and at the predetermined time point an intraorbital blood sample is taken to determine circulating antibody levels; 3) a microdialysis sample of sufficient volume for analysis is taken at the protocol's pumping rate; 4) at the end of the analyte sampling another intraorbital sample is taken to determine anti-IL31 circulating levels.

A multiplex analysis of Analyte and plasma is performed by Luminex and quantification determined for, 1.) anti-IL31 antibody, 2.) anti-mouse-IgG as a depletion/diffusion control, and 3.) anti-mouse Hemoglobin to control for microdialysis insertion trauma and blood vessel damage. Using the ex vivo determined membrane parameters and the measured influx rate of anti-IL31 into the analyte at a given circulating antibody concentration, an estimate of the skin diffusion rate is determined. The concentration of mouse IgG in the analyte is used to evaluate local depletion of proteins near the probe. A formula may need to be devised to compensate for local depletion in the diffusion analysis.

Example 9 Constructs for Generating a Human IL-31Ra/OncostatinM Receptor (OSMRbeta) Heterodimer

A system for construction, expression and purification of such soluble heterodimeric receptors is known in the art, and has been adapted to the receptor pair, human oncostatin M receptor (OSMRbeta) and human IL-31Ra. For this construct, the polynucleotide for the soluble receptor for OSMRbeta is shown in SEQ ID NO: 17 and corresponding polypeptide is shown in SEQ ID NO:18; and the polynucleotide for the soluble receptor for human IL-31Ra is shown in SEQ ID NO:20 and corresponding polypeptide is shown in SEQ ID NO:21.

To construct a cell line expressing a secreted soluble hIL-31Ra/human OSMRbeta heterodimer, a construct was made so that the resulting heterodimeric soluble receptor comprises the extracellular domain of human OSMRbeta fused to the heavy chain of IgG gamma1 (Fc4) with a Glu-Glu tag at the C-terminus; while the extracellular domain of IL-31Ra was fused to Fc4 with a His tag at the C-terminus. For both of the hIL-31Ra and human OSMRbeta arms of the heterodimer a Gly-Ser spacer of 12 amino acids was engineered between the extracellular portion of the receptor and the N-terminus of Fc4.

A. Construction of Human Soluble OSMRbeta/Fc4-CEE

For construction of the human soluble OSMRbeta/Fc4-CEE portion of the heterodimer the extracellular portion of human OSMRbeta was isolated using PCR with oligos under PCR reaction conditions as follows: 30 cycles of 95° C. for 60 sec., 57° C. for 30 sec., and 72° C. for 100 sec.; and 72° C. for 7 min. PCR products were purified using QIAquick PCR Purification Kit (Qiagen), digested with EcoR1 and BglII (Boerhinger-Mannheim), separated by gel electrophoresis and purified using a QIAquick gel extraction kit (Qiagen).

The expression cassette, plasmid backbone and Fc4-GluGlu tag portion of the chimera were contained within a previously made in house plasmid vector. The plasmid vector was digested with EcoR1 and BamH1 (Boerhinger-Mannheim), separated by gel electrophoresis and purified using a QIAquick gel extraction kit (Qiagen). The digested and purified fragments of human OSMRbeta and Fc4-cEE containing plasmid were ligated together using T4 DNA Ligase (Life Technologies, Bethesda, Md.) using standard ligation methods. Minipreps of the resulting ligation were screened for an EcoRI/Sma1 insert of the correct size (772 bp) for the soluble OSMRbeta and positive minipreps were sequenced to confirm accuracy of the PCR reaction. This new plasmid construction is termed pZP9-ONCOMR-Fc4CEE.

B. Construction of Human Soluble IL-31Ra/Fc4-CHIS

For construction of the hIL-31Ra/Fc4-CHIS portion of the heterodimer, the extracellular portion of human IL-31Ra was isolated by digestion of a plasmid previously containing IL-31Ra-Fc4 soluble receptor. The plasmid was first digested with Sal1 (New England Biolabs, Beverly, Mass.) after which the reaction was serially phenol chloroform extracted and ethanol precipitated. The digested DNA was then treated with T4 DNA Polymerase (Boerhinger-Mannheim), to fill in the 5′ overhangs created by the Sal1 digestion, leaving the DNA ends blunt, after which the reaction was serially phenol chloroform extracted and ethanol precipitated. The blunted DNA was then further digested with BglII to cut at the 3′ end), separated by gel electrophoresis and purified using a QIAquick gel extraction kit (Qiagen) as per manufacturer's instruction. The resulting DNA fragment containing the sequence coding for the extracellular domain of IL-31Ra was ligated into an Fc4-CHIS tag containing mammalian expression vector prepared as follows.

The expression cassette, plasmid backbone and Fc4-CHIS tag portion of the chimera were contained within a previously made in house plasmid vector. This plasmid vector was digested with EcoR1 (Boerhinger-Mannheim) after which the reaction was serially phenol chloroform extracted and ethanol precipitated. The digested DNA was then treated with T4 DNA Polymerase (Boerhinger-Mannheim), to fill in the 5′ overhangs created by the EcoR1 digestion, leaving the DNA ends blunt, after which the reaction was serially phenol chloroform extracted and ethanol precipitated. The blunted DNA was then further digested with BamH1 (Boerhinger-Mannheim) to cut at the 3′ end, separated by gel electrophoresis and purified using a QIAquick gel extraction kit (Qiagen). The digested and purified fragments of human IL-31Ra and Fc4-CHIS containing plasmid were ligated together using T4 DNA Ligase (Life Technologies, Bethesda, Md.) using standard ligation methods.

Minipreps of the resulting ligation were screened by PCR using a IL-31Ra specific sense primer and a Fc4 specific antisense primer with the following PCR reaction conditions: 30 cycles of 94° C. for 60 sec., 68° C. for 150 sec; and 72° C. for 7 min. An expected product size of 848 by confirmed the correct assembly of the plasmid termed pZEM228 hIL-31Ra/Fc4HIS.

A second IL-31Ra-Fc4 construction was created for use in generating homodimer protein from COS cells. Briefly the coding region for the full fusion protein was isolated by digestion of a plasmid previously containing IL-31Ra-Fc4 soluble receptor with Sal1 (Boerhinger-Mannheim). The reaction was serially phenol chloroform extracted and ethanol precipitated. The digested DNA was then treated with T4 DNA Polymerase (Boerhinger-Mannheim), to fill in the 5′ overhangs created by the EcoR1 digestion, leaving the DNA ends blunt, after which the reaction was serially phenol chloroform extracted and ethanol precipitated. The blunted DNA was then further digested with Not1 (Boerhinger-Mannheim) to cut at the 3′ end, separated by gel electrophoresis and purified using a QIAquick gel extraction kit (Qiagen). A mammalian expression vector containing a CMV driven expression cassette was digested to generate compatible ends and the 2 fragments were ligated together. Minipreps of the resulting ligation were screened by PCR using vector specific sense primer and IL-31Ra specific antisense primer with the following PCR reaction conditions: 30 cycles of 94° C. for 30 sec., 64° C. for 30 sec; 70° C. for 90 sec; and 72° C. for 7 min. An expected product size of approximately 1000 by confirmed the correct assembly of the plasmid termed pZP7NX-hIL-31Ra-Fc4. This plasmid was subsequently transfected into COS cells using Lipofectamine (Gibco/BRL), as per manufacturer's instructions. The cells were conditioned for 60 hours in DMEM+5% FBS (Gibco/BRL) after which the protein was purified over a protein G-sepharose 4B chromatography column and made available for in vitro bioassays, for example, such as those described herein.

C. Generating a Human IL-31Ra/OncostatinM Receptor (OSMRbeta)

About 16 μg each of the pZP9-ONCOMR-Fc4CEE and pZEM228 hIL-31Ra/Fc4HIS were co-transfected into BHK-570 (ATCC No. CRL-10314) cells using lipofectamine (Gibco/BRL), as per manufacturer's instructions. The transfected cells were selected for 10 days in DMEM+5% FBS (Gibco/BRL) containing 0.5 mg/ml G418 (Gibco/BRL) and 250 nM methyltrexate (MTX)(Sigma, St. Louis, Mo.) for 10 days.

The resulting pool of doubly-selected cells was used to generate the heterodimeric protein. Three cell Factories (Nunc, Denmark) of this pool were used to generate 10 L of serum free conditioned medium. This conditioned media was passed over a 1 ml protein-A column and eluted in (10) 750 microliter fractions. Four of these fractions found to have the highest concentration were pooled and dialyzed (10 kD MW cutoff) against PBS. The desired heterodimeric soluble IL-31Ra/OSMRbeta protein complex was isolated from other media components by passing the pool over a Nickel column and washing the column with various concentrations of Imidazole. The soluble IL-31Ra/OSMRbeta protein eluted at intermediate concentrations of Imidazole, while hIL-31Ra/Fc4HIS homodimer eluted at higher concentrations of Imidazole.

From the foregoing, it will be appreciated that, although specific embodiments of the invention have been described herein for purposes of illustration, various modifications may be made without deviating from the spirit and scope of the invention. Accordingly, the invention is not limited except as by the appended claims. 

1. A method of treating pain in a mammal, comprising administering to the mammal an IL-31RA or OSMRb (Oncostatin M receptor beta) antagonist, wherein said antagonist is an antibody or soluble receptor, and wherein the pain is reduced, limited, minimized or neutralized.
 2. The method of claim 1, wherein the IL-31Ra or OSMRB antagonist binds a polypeptide comprising the amino acid sequence of SEQ ID NO: 2 from residue 27 to residue
 164. 3. The method of claim 1, wherein said antagonist is an antibody binding IL-31RA, OSMRb or both.
 4. The method of claim 1, wherein the antagonist is a soluble receptor comprising one or more soluble IL-31Ra subunits.
 5. The method of claim 1, wherein the antagonist is administered to neuronal tissue comprising dorsal root ganglion or spinal cord tissues.
 6. The method of claim 3 wherein said antibody is selected from the group consisting of: anti-idiotype antibodies; antibody fragments; bispecific antibodies; diabodies, linear antibodies, multivalent antibodies, multispecific antibodies; chimeric antibodies; and humanized antibodies.
 7. The method of claim 6 wherein said antibody fragment is selected from the group of fragments consisting of: Fab, Fab′; F(ab′)₂; Fv and single chain antibodies.
 8. The method of claim 3 wherein said antibody is an isotype selected from the group consisting of: IgG; IgG1; IgG4; IgM; IgA; IgD; and IgE.
 9. The method of claim 3 wherein said isotype is IgG.
 10. The method of claim 3 wherein said antibody is a monoclonal antibody.
 11. The method of claim 3 wherein said antibody is a humanized monoclonal antibody.
 12. The method of claim 11 wherein said antibody is an IgG isotype.
 13. The method of claim 4 wherein said soluble IL-31RA subunit comprises the amino acid sequence of SEQ ID NO:20.
 14. The method of claim 4 wherein said soluble receptor is a soluble multimer.
 15. The method of claim 14 wherein said multimer is a heterodimer comprising a soluble IL-31RA subunit and an OSMRbeta subunit.
 16. A method of reducing pain in a patient in need thereof comprising administering an antibody that antagonizes the IL-31RA subunit, wherein said antibody is a monoclonal antibody.
 17. The method of claim 16 wherein said monoclonal antibody is a humanized monoclonal antibody.
 18. The method of claim 16 wherein said antibody is an IgG isotype.
 19. A method of reducing pain in a patient in need thereof comprising administering a soluble receptor comprising one or more soluble IL-31Ra subunits.
 20. The method of claim 19 wherein said soluble receptor is a heterodimer comprising a soluble IL-31RA subunit and an OSMRbeta subunit.
 21. A method of reducing pain in a patient in need thereof comprising administering an antibody that antagonizes a heterodimer comprising an IL-31RA subunit and an OSMRbeta subunit (Oncostatin M receptor beta), wherein said antibody is a monoclonal antibody.
 22. The method of claim 21 wherein said monoclonal antibody is a humanized monoclonal antibody.
 23. The method of claim 21 wherein said antibody is an IgG isotype. 